Adaptive control of redundant multilink robot using fussy logic

The kinematics model of multilink robot manipulator involves solution of the inverse problem. The use of fuzzy logic based linguistic rules demonstrates superior performance over classical, computationally intensive and yet approximate solutions for the target position control and tracking control of multilink robot arm. A new approach to fuzzy distance and restriction measures is used to obtain the appropriate orientations of the links for avoiding obstacles in the robot trajectories. This approach eliminates the classical task of solving highly coupled, nonlinear equations describing the illposed inverse problems of multilink robot motion at a much less demanding computational time. Such clear advantage of fuzzy logic based adaptive controller are illustrated by simulation results of guidance of a multilink robot in target positioning and trajectories tracking. The simulation results involve a threelink robot arm with capability of moving from one position to any desired position and tracking defined trajectories accurately. A modified fuzzy rule based distance measure allows the robot to follow trajectories without hitting the obstacles in the path. The simulation results indicate the advantage of fuzzy logic based adaptive controllers in multiple criteria decision-making tasks.